Bald eagles everywhere; snowy owls stealing show

Delaware and the entire Northeast, especially along the coast, continue to be enthralled by the invasion of snowy owls this winter. Jim White, who coordinates Christmas bird counts up and down Delaware for the Delmarva Ornithological Society, said the owls are definitely the bird story of the year for Delaware.

“We have them up here in New Castle County, at Prime Hook and Bombay Hook national wildlife refuges, at Port Penn, Cape Henlopen State Park and Delaware Seashore State Park,” said White.

“The latest theory is that last summer, conditions were so good in the Arctic, the owls bred like crazy. So many reproduced that it created the biggest irruption of snowy owls ever recorded, by far.”

Because there was such a huge reproduction of the owls, the oncoming winter forced the young owls to the coast and southward to find food. Irruption is the term used to define a sudden rushing into an area by something, such as has happened along the northeast coast of the U.S. with the owls. Part of the exceptional conditions last summer may have been bountiful populations of lemmings and voles - rodents - that make up a large part of the owls’ summer diet. [Take a look at a photograph included with this column at capegazette.com showing 70 dead lemmings and voles brought to a ground-level nest by parent owls for food even before the four eggs in the nest hatched.]

Owls can lay anywhere from two to 10 eggs, and when there’s plenty of food, many of them can survive until winter, when competition for scarcer food drives them elsewhere to hunt.

According to articles at Cornell University’s eBird.org website, scientists are studying whether climate change in the Arctic - such as a shrinking polar ice cap - is contributing to population variations in creatures like lemmings and owls.

Delaware’s bay shore and coast offer ideal expansion areas for the owls because of the wide-open marshes and dunes, and their attendant populations of rodents, ducks and other sea birds that the owls hunt and eat.

White and a few teams of volunteers will spread out across Sussex County this weekend to gather observations for the Audubon Society’s annual Christmas Bird Counts. Those counts of any species of birds they can find, and their approximate numbers, help gauge the health of bird populations across the U.S.

White said records show there were snowy owl irruptions back in the 1800s, but none to rival what’s been seen this year. “Of course, back then the response to them was different,” said White. “People shot them for their feathers. I saw a picture recently, from back then, showing a big shed full of dead snowy owls.”

Meanwhile, lots of bald eagles

Just as many avid bird watchers have seen more snowy owls this year than at any other time in their lives, that’s the way it is for me with bald eagles. I’ve been seeing plenty - singles, twos and threes - whereas 10 years ago, one or two sightings of eagles in a year would have been memorable. But those are piker numbers compared to what Harry Joseph told me recently.

He said that back during the shotgun deer season in November, his son and other hunters set out a few deer hides in the middle of a field on one of their farms in the Cool Spring area. “My son counted 28 or 29 eagles on the ground around those carcasses one Sunday morning - mature and immature. We’ve seen them in the teens and low 20s the last few years, but never that many before. They sure can find those deer hides.”

Anthony Gonzon, director of Delaware’s bald eagle monitoring program, said what the Josephs saw is not unprecedented in Delaware. “In January of 2011, we went to a farm field near Chorman’s Airport in the Greenwood area. We counted at least 70 bald eagles there. They were eating whatver kind of fertilizer the farmer was putting down. Probably something to do with chicken.”

Farmers like Joseph don’t mind the eagles hanging around their winter wheat fields. They help scare out snow geese, which have a real fondness for tender wheat shoots. Joseph’s sons have staked out oversized and painted eagle silhouettes in fields they till along Route 24. “They work for a while, but then the geese get used to them and start to pitch in again,” Joseph said.

Jim White said the No. 1 reason for increasing populations of bald eagles is that they’re breeding everywhere so much better than they ever have before. “So there are more nesting pairs than ever in Delaware, and this is also a great place for them to overwinter. We rarely ever get a total ice-out, and there’s so much food for them between snow geese and dead deer - whether it’s carcasses or roadkill.”

White said bald eagles are into courtship flights and chattering this time of year. “They’re thinking about nesting right now.”

Gonzon said Delaware is currently monitoring more than 75 nests across the state. “Those nests produced 105 chicks last year.” He said state biologists and others across the U.S. will be conducting a midwinter eagle count next week to gauge the health of the population of our national bird. Needless to say, Gonzon expects to find Delaware’s bald eagle population in very healthy shape.

This photograph from the Bruce Mactavish Newfoundland Birding Blog shows a snowy owl nest in northern Quebec in 2013 with 70 lemmings and 8 voles brought to the nest by the parent owls even before the eggs have hatched. No wonder so many snowy owlets survived this year.
(Photo by: J.F. Therrien, Arctic Raptors Facebook page)

Scott Becque found this snowy owl in the dunes at the point of Cape Henlopen this week.
(Photo by: Scott Becque)